What is CVE-2020-13486?

CVE-2020-13486 is a medium-severity vulnerability in Verbb Knock, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2020-05-25.

How severe is CVE-2020-13486?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Open Redirect in Verbb Knock

CVE-2020-13486

The Knock Knock plugin before 1.2.8 for Craft CMS allows malicious redirection.

Vulnerability class: Open Redirect

Published 2020-05-25 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (50.5th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 50.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Verbb Knock

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

References

github.com/verbb/knock-knock/blob/craft-3/CHANGELOG.md (Third Party Advisory, Release Notes)

Frequently asked questions

What is CVE-2020-13486?: CVE-2020-13486 is a medium-severity vulnerability in Verbb Knock, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2020-05-25.
How severe is CVE-2020-13486?: Medium severity. CVSS v3 base score is 6.1 out of 10.